Apparently these are produced by the systemd software watchdog feature enabled in the service file by WatchdogSec= setting. While I appreciate the usefulness of this feature, I fail to see the sense in filling the log with crap it produces. I've had little success in figuring out exactly why these started to appear after updating systemd and thus I unfortunately have no idea how to prevent these from being logged.

Perhaps someone could point me to right direction as to where to tweak?